Spotlights

[Research News] Managing Stiffness in Deep Calf Muscles Using Ultrasound Stimulation

Research shows ultrasound stimulation can reduce passive stiffness in the soleus, suggesting potential for non-invasive management of deep muscle stiffness

A team of researchers led by Professor Tatsuya Hojo of the Faculty of Health and Sports Science has reported that just 10 minutes of ultrasound stimulation can reduce stiffness in the soleus, a deep calf muscle that is difficult to target using conventional interventions. Because passive muscle stiffness is associated with an increased risk of muscle strain injuries, these findings provide new insight into a simple, non-invasive approach for managing stiffness in deep muscles and may contribute to future strategies for sports injury prevention and rehabilitation.

Reference
Tomohiro Umeda, Kaho Sugiyama, Hanaka Hirasawa, Ryosei Sakurada, Taku Wakahara, Tatsuya Hojo, The effects of ultrasound stimulation on passive muscle stiffness of triceps surae, Journal of Biomechanics, Volume 206, 2026
https://doi.org/10.1016/j.jbiomech.2026.113502

Image title: Ultrasound stimulation reduces passive stiffness in the deep soleus muscle
Image caption: Ultrasound stimulation was applied to the calf for 10 minutes, and passive muscle stiffness was assessed using shear wave velocity. The study compared the superficial medial gastrocnemius (MG) and deeper soleus (SOL) muscles. Passive muscle stiffness decreased in the SOL after ultrasound stimulation, while no significant change was observed in the MG.
Image credit: Mr. Tomohiro Umeda from Doshisha University, Japan 
Image link: N/A
License type: Original content
Usage restriction: Credit must be given to the creator.